Such water supply systems are counted as belonging to the state of the art and are applied in varied manners. A known water supply system of this type is marketed by the applicant under the description Grundfos MQ. This water supply system comprises a housing which essentially provides for the arrangement of an electric motor with a multistage centrifugal pump which is arranged thereafter and which is with a horizontal, i.e. lying drive axis. The housing which otherwise consists of plastic, in the region of the centrifugal pump is lined with a stainless steel pot which at the face side comprises a water inlet connection. A cuboid housing part is saddled onto the barrel-like housing at the motor side and this housing part houses a diaphragm tank as well as the electric/electronic control and the electrical connection. The outlet connection is arranged between this housing part and the pot-like stainless steel housing.
Although this water supply system has proven its worth, however it is also costly in manufacture and assembly due to its complicated design.